To prohibit the possession or transfer of junk guns, also known as Saturday Night Specials.

Amends the Brady Handgun Violence Prevention Act to prohibit the possession or transfer of a junk gun (defined as a handgun that is not a sporting handgun, as determined by the Secretary of the Treasury, and any combination of parts from which such handgun can be assembled) which has been shipped or transported in interstate or foreign commerce. Makes this provision inapplicable to the continuous and otherwise lawful possession of a junk gun by a person during any period that began before this Act's effective date. Sets penalties for violations.